This invention relates in general to magnetic tape cassette storage and record/reproduce apparatus, and, more particularly, to a magnetic tape cassette accessor which inserts and extracts cassettes at cassette storage locations and record/reproduce location and grips a cassette for transport between locations.
In applications in which a large amount of information is stored in a plurality of magnetic tape cassettes of different sizes and used in one or more record/reproduce locations, it is desirable that each magnetic tape cassette, be accessed in a minimum amount of time. For example, it is desirable to minimize the time required to change over from one cassette to another cassette used at a magnetic tape record/reproduce device. Where the cassette storage system includes a large number of cassette storage compartments, it is also desirable that the cassette be handled and transported between a storage compartment and a record/reproduce device, in a gentle and reliable manner. Different sizes of cassettes should be accommodated without having to use different cassette handling devices.
Various arrangements have been proposed to transport an object between spaced locations in a storage system. The simplest type of arrangement uses manual power for actuation of the transport system and for loading and loading articles at storage locations. (See: U.S. Pat. No. 4,113,119, issued Sept. 12, 1978, entitled APPARATUS FOR LOADING ARTICLES ONTO VERTICALLY SPACED HORIZONTALLY DISPOSED SHELVES.) Although such an arrangement is relatively inexpensive, it is disadvantageous because it is not readily adaptable for use as an automatic storage and handling system. In order to ameliorate this deficiency in manual transport and handling systems, it has been proposed to use motors in order to actuate the transport assembly. Typically, at least one or more of the actuating motors are mounted on the transport assembly itself. (See, for example, U.S. Pat. No. 3,557,977, issued Jan. 26, 1971, entitled LOAD DETECTING DEVICE FOR WAREHOUSING SYSTEM, and U.S. Pat. No. 4,614,474, issued Sept. 30, 1986, entitled DEVICE FOR EXCHANGING DISKS.) However, drive motors and drive motor supports, add considerable weight to the transport assembly, thus increasing the stresses on the transport assembly drive and on the transport assembly load-bearing components. Moreover, reliability is reduced and maintenance is made more difficult.
Automatically operated, article gripping mechanisms are disclosed in U.S. Pat. No. 3,630,391, issued Dec. 28, 1971, entitled "Work Gripper", and U.S. Pat. No. 2,894,616, issued Jul. 14, 1959, entitled "Automatic Material Handling Mechanism". In both patents, the gripping mechanisms are actuated by pneumatic power sources mounted on the mechanisms. This is disadvantageous due to the weight of the mechanism and the necessity of using moving conduits for the actuating fluid.